Our nation faces a multi-trillion dollar problem in deteriorated infrastructure. The submerged or subterranean portion of many if not most decades-old distribution pipelines, a portion often out of sight and out of mind, is at great risk and in dire need of maintenance, especially cleaning. Affected business and municipal sectors include power generation, petroleum, water, and wastewater management. Analyzing the need, clarifying by example, establishing requirements, and identifying the limitations and disadvantages of the prior art in terms of those requirements can best accomplish proper understanding of these unsolved issues.
When designated for periodic maintenance, infrastructure remediation is often postponed due to lack of budget in the face of the inefficiencies and high costs of available, prior art solutions. Such postponement only further complicates the maintenance problem and increases costs when the problem is eventually addressed. An apparatus, able to operate at high efficiency and low cost, is required in order to change maintenance from “often deferred” (e.g., maintenance performed when unavoidable and when budget and other constraints permit) into “routine” (i.e., periodically scheduled maintenance). The infrastructure could then be included in scheduled plant maintenance procedures, resulting in ongoing infrastructure operation at original design specification.
Furthermore, the engineering of the original designs and structures tends to become degraded as living organisms encounter and exploit these created ecological niches, for example, as Zebra Mussels adhere to and grow within conduits. Such ‘marine fouling’ has become a significant and costly problem, and serves as a prime example of both the operation of evolution and of unintended and unsuspected consequences.
The power generation sector depicts one example of the enormity of the problem of fouling and attendant deterioration of a submerged infrastructure. High volumes of water are required in steam electric generation plants to remove waste heat from steam condensers. About one-half of all larger power plants utilize an open loop (a.k.a. oncethrough) cooling system (FIG. 2) for this purpose (versus closed loop—for example, recycling water in cooling towers). These systems incorporate submerged intake and discharge conduits, highly susceptible to fouling, and raise environmental concerns.
Effective conduit size is dramatically reduced by even a relatively small amount of fouling on the inside of any conduit. Over and above the reduction of volume, the rough surface of fouling creates friction, causing internal turbulence and effectively compounding the restriction of flow rates. Pumping pressure must then increase to restore the flow rates to that required for cooling.
Unfortunately, achieving higher flow rates via increased pumping pressure requires an exponential increase in pumping horsepower, and in the associated costs. A single large power plant might have to divert millions of dollars worth of electricity for such pumping; electricity that otherwise could be placed onto the power grid. The extra pumping pressure then also puts greater strain and wear on the infrastructure, decreasing its safety and operative life.
Left un-maintained, any growing restriction in diameter will eventually overcome the ability of pumps to provide the required water volume and compensate for the restriction. Plant boiler heat must then be reduced to relieve the potential of backpressure on the steam turbines. Reducing boiler heat impacts electricity production, creating a second source of revenue loss.
Using pumping pressure to increase flow rates has a negative environmental impact as well. As flow rates increase, plankton, fish or even marine mammals are more likely to become sucked into these conduits and die. Regulatory bodies, seeking compliance with the Clean Water Act, and to mitigate entrainment among other issues, are proposing regulatory limits to cooling water flow rates (see, for example, Fish Protection at Steam Electric Power Plants, Electric Power Research Institute, 2009). The removal of marine fouling and sediments from cooling water conduits, so as to increase flow volume, will be the only remaining alternative to increase steam condenser performance.
However, removal of marine fouling is a complex problem. Conduits may have a variety of cross-section geometries that may incorporate angles, changes in diameter, and obstacles. Obstacles may include debris, broken or misaligned infrastructure (such as joints), or infrastructure protuberances (such as curves, slopes, corners, valve bodies and gateways).
When removing marine fouling, the calcified “footprint” deposited by crustaceans must be completely removed, as any remaining traces will support a rapid re-infestation. This complete removal must be accomplished without damaging the underlying work surface. Fouling also never—or ‘almost never’—occurs in a uniform layer. During removal, varying thicknesses and densities must be detected and proper corrections made to the rate of axial transit through the conduit, the “bite” of the debris removal mechanisms, and debris recovery processing rates. New regulatory compliance requirements for debris disposal also impact these adjustments.
The volume of debris removed in the remediation of a larger conduit, may approach a ton per lineal foot. An individual chunk of dislodged debris, falling to the floor (i.e., the “invert”) of the conduit, may encompass several cubic feet, weigh hundreds of pounds, and create a very significant work process obstacle. It also may pose a significant safety hazard to a human diver in an enclosed environment, particularly if visibility is poor, as it tends to be when water is turbid and lighting is both restricted and limited.
Extensive research regarding submerged infrastructure remediation has identified the failure modes and inadequacies of prior art. The example in the last section, and focus on submerged pipes or conduits (exemplifying a common type of submerged infrastructure), is illustrative of prior art limitations. The overall failure of the prior art for remediation of submerged infrastructures can be summarized by the simple fact that labor-intensive manual procedures are and will remain central (“DAM Good ROV”, Oceanology Today, Jan. 1, 2006, especially the second paragraph). No prior art device eliminates the need for manual procedures performed by divers and surface crews without significant disadvantages and limitations (either to address intended functionality or to provide a complete solution).
Requirements for remediation success in the submerged environment include business metrics that are characterized by cost, safety and efficiency. These metrics impact the ability of industry and government to implement any form of remediation and may be broken down into functional requirements. For a given remediation approach to be ultimately effective, it must at least include and address Inspection, Navigation, Scalability, Optimization, and Performance.
These requirements will be referred to jointly via the acronym “INSOP” hereinafter. INSOP provides a common reference point from which to review alternative approaches for remediation of infrastructures.
Until the disclosure of this invention, limitations of prior art have failed to achieve the performance automation required to meet safety, cost or efficiency benchmarks. This failure prevents industry or government from remediating infrastructure in any meaningful way. Apparatus in the prior art may be classified into (1) devices for manual use, (2) semi-automated devices, and (3) fully-automated devices.
Manual methods either incorporate de-watering (as used herein, the term “de-watering” is used broadly to mean removing water, sewage, mud, oil, sludge, or other material so as to expose a submerged or otherwise unexposed infrastructure) to allow traditional forms of remediation, or incorporate the use of divers. Divers obviously are not automated apparatus and, at best, use diver-operated tools. More importantly, divers always must put their lives ‘at risk’ in hazardous environments and in particular, the penetrating into long conduits where there is no direct access to the surface.
Semi-automated methods involve a mechanical apparatus having some form of automated control that makes it less reliant upon diver-operation. These require a user's immediate and continued attention at the remote or monitoring end of the mechanical apparatus, and generally also require considerable experience and skill in order to correctly interpret a limited and indirect set of signals into a reasonable apperception of the events and conditions at the ‘cutting edge’ of the remote apparatus. The further removed, and the more different, the environment is from that experienced by the operator, the more likely it will be that interpretation will introduce errors. Furthermore, semi-automated methods still require divers to overcome limitations of the mechanical apparatus (e.g., tasks the apparatus cannot perform) or to correct failures in its automated control apparatus. The more removed the operator is from both the apparatus and the environment, the more limited the operator's knowledge of the actual conditions—of the environment and of the apparatus—will be; and the more likely it becomes that an unanticipated and un-sensed divergence from the presumed condition will give rise to a problem or even a disaster.
Fully automated methods do not require either an operator's or a diver's immediate and continual attention and continued involvement, but are limited in the types of tasks or environments in which they can perform. For example, the prior art may disclose an apparatus with the ability to perform some level of inspection in an automated fashion, but the same apparatus cannot perform remediation. Alternatively, the prior art may disclose an apparatus with the ability to remediate a round, small diameter conduit, but unable to negotiate obstacles. In all fully automated examples (i.e., autonomous) of prior art apparatus for submerged infrastructure remediation, (e.g. power plant cooling systems), divers must be used to compensate for numerous limitations, a serious, hazardous, and costly disadvantage.
Submerged infrastructure may be manually remediated by de-watering or by using divers. De-watering permits remediation by traditional land-based techniques. Unfortunately, as infrastructure ages it becomes more fragile and de-watering case histories, chronicling significant structural damage and even collapse, have made de-watering a practice of last resort. Furthermore, the nature of the submerged infrastructure or the material in which it is submerged may make de-watering impractical or even impossible. Deploying divers is the oldest, and still perhaps the most prevalent practice to either avoid de-watering, or to remediate infrastructure where de-watering is not an option.
The manual method of using of divers (FIG. 1A) is the lowest common denominator, and least efficient means to meet INSOP functionality. It has significant disadvantages and limitations. Divers are dependent on visibility for inspection and navigation, which decreases rapidly as a function of turbidity, so that divers must rely on “feel” by the use of hands or feet. Navigation is a further limited by available air supply, tethers, support divers, and safety requirements. Scalability is limited by diver's reach, which must be augmented by erecting scaffolding and adding additional dive teams. Divers are limited to work processes that can be performed using hand-held or handcontrollable implements, and work optimization is limited by human perception, motor control, and responses. Performance is a function of environmental conditions (pollution, temperature, clarity and current); of manual labor, susceptible to fatigue caused by the heavy weight belts that must be worn to offset the kickback of hand-operated implements; and the number of divers that can work within confined conditions without mutual interference and increased hazard.
The prior art includes apparatus to help overcome diver limitations. For divers using water blasters, one such approach is to increase the ablative capability of a given water pressure by replacing the fixed fan spray pattern of the water jet with a specialized nozzle (see, for example, Phovarov, U.S. Patent Pub. No. 2006/0151634 A1). Given the limitations of the divers as explained above, positioning errors result in unacceptable abrasion to the work surface by the more powerful cutting action. Limitations include the lack of means to exactly position this nozzle to the work surface, control the amount of abrasion, and to control uniformity.
Another prior art approach (see, for example, Templet, U.S. Pat. No. 5,431,122), intended to improve diver productivity in the rate of the removal of bio-fouling, resulted in an apparatus resembling an underwater lawn mower. A limitation of this apparatus was the inability to cut more than a “swath” of a few feet wide in any single pass, requiring multiple passes. Other limitations included the lack of navigation aids to maintain a straight cutting swath, blinding of the diver caused by the turbidity of machine operation, and no means to prevent the deadly potential of crushing or drowning of the diver by entanglement should power to the machine be lost and it free falls from the work surface.
To overcome the limitations of the manual performance of divers, prior art has introduced semi-automated methods in the creation of apparatus that, for example, has incorporated mechanical scrapers or water jets for debris removal. Such apparatus may be, for example, towed by wire cable, pushed by hydraulic pressure, or moved by selfpropulsion. Semi-automated capability ranges from non-intelligent apparatus such as pipeline pigs (FIG. 1B) or other cleaners, to the Remote Operated Vehicle (“ROV” hereafter) utilizing the intelligence of a human being as its operator (FIG. 1C). A general limitation of this method is that all semi-automated approaches still must incorporate diver-operation and divers to overcome limited functionality.
Pipeline pigs (see, for example, Couchman, et. al., U.S. Pat. No. 6,538,431 B2), proven successful in closed systems such as oil pipelines, have been adapted for use in submerged infrastructure such as conduits. The pipeline pig, propelled by hydraulic pressure, breaks debris loose from the conduit walls as it is forced through the conduit. One limitation of these devices is they impede operational flow in requiring a bulkhead to be placed over the conduit mouth to complete the seal with the conduit.
Disadvantages and limitations of pigs are numerous. The pig simply pushes ahead, without any ability to acquire data about the environment and work surface, or to analyze or control the remediation work process as it proceeds. Without the ability to remove accumulated debris or to optimize work processes in response to conditions, accumulation builds in the path of the pig until such time as it becomes stuck. This further creates a navigation problem, as the pig, unable to avoid an obstacle, merely crashes into it. Pigs are not a scalable solution: A different size of pig is required for each size of conduit diameter. As diameters increase, the pig becomes disproportionately less effective. Further disadvantages that impact performance include a lack of means to insert itself into a conduit, supply its own hydraulic pressure, completely clean a conduit in a single pass, free itself when stuck, or to recover the debris that it has dislodged. The Sea Pig (Pipeline Digest, Jul. 4, 1983, “A pig for every pipe”) exemplifies the above disadvantages and limitations. This multi-ton projectile, the largest pig of its time, was eventually abandoned for its inability to adequately clean a mere twelve-foot conduit as well as for its tendency to get stuck in the conduit.
Another prior art approach uses the operational flow of water harnessed to rotate mechanical scrapers in the attempt to overcome limitations of the pig (see, for example, Crocco, U.S. Pat. No. 5,146,644). One limitation of this prior art is the requirement of flowing water to rotate fan blades as a (ineffective) source of power. Another limitation is the use of rotating mechanical scrapers without means to prevent their jamming up when encountering a large clump of debris and causing the device to become stuck.
Yet other prior art uses a wire tow cable as a means to move a cleaning apparatus. One such prior art approach (see, for example, Haynes, U.S. Pat. No. 2,201,680) uses the forward progress of the apparatus as the means to power the rotation of mechanical scrapers. In addition to requiring a tow cable, other limitations include the requirement of means to divide towing power between moving the apparatus forward, and rotating its scrapers. This division increases the risk of the apparatus getting stuck or breaking the tow cable.
To reduce the strain of the towing cable, other prior art used external hydraulic power to rotate the scrapers (see, for example, Latall, U.S. Pat. No. 3,740,785). One limitation is the need to supply hydraulic power through a long hose from the surface down to the rotating the scraper motor. Line loss through the hose results in significant power drop. Yet another prior art approach (see, for example Clavin, U.S. Pat. No. 4,027,349) suggested compound rotation as a means to provide some latitude in engaging varying amounts of debris and slight variations in the size of conduits. A set of arms rotated around the axis of the conduit and presented a set of spring-loaded and spinning scrapers to ride over variations in the conduit surface. These limitations represent considerable complexity in apparatus, yet do not provide other than passive means to detect and overcome even minimal surface variations, let alone large obstacles.
Furthermore, compound rotation doubles hydraulic power requirements. Still other prior art (see, for example, Murphy, U.S. Pat. No. 5,069,722 or Rufolo, U.S. Pat. No. 5,444,887) has elaborated upon the single apparatus to include support equipment such as cranes, tow cable guidance systems, and catch basins to try and capture some portion of loosened debris.
Another body of proposed prior art has attempted to use water jetting technology to replace mechanical scrapers. In principle, water jets do not need to make direct contact with the work surface and are not susceptible to getting the apparatus stuck. Early versions of the water jet apparatus incorporated a reduced diameter, sled-like frame designed to enable towing by wire. A disadvantage of this approach was the “kickback” of the jets, buffeting the sled, and causing the sled runner to get stuck at the joints between sections of conduit. The cable would sometimes snap, or the jets would to stay in one place too long and abrade the surface. Yet other prior art exchanged the sled for a “pipe crawler”. Motorized wheels and auxiliary propulsion allowed for a more reliable engagement with the conduit surface and this created a more constant transit (see, for example, Hammelmann, U.S. Pat. No. 3,155,319 and Geppert et. al., Patent Pub. No. 2010/0139019 A1). This required yet more motors, increasing power requirements and line loss.
The above prior art, consisting of both non-intelligent and semi-automated methods, beyond the various individual limitations and disadvantages, fail to address INSOP requirements. This failure manifests in an over dependence upon manual methods, such as divers below and large support crews above the surface. With over dependency on manual methods and human participation, these examples of the prior art become economically infeasible.
A Remote Operated Vehicle (“ROV” hereinafter) incorporates the intelligence of a human operator for control. An ROV (FIG. 1C) is a submersible vehicle featuring an umbilical that serves as a tether and a connection to a surface source of power and human control that is aup iented by closed circuit video capability.
ROV technology has a growing application in the remediation of submerged infrastructure as disclosed, for example, in “Remotely Operated Vehicle [ROV] Technology: Applications and Advancements at Hydro Facilities,” Electric Power Research Institute (EPRI), 2002. This EPRI study identifies basic types of ROV and discusses their relative operational effectiveness.
The study differentiates operational activities into instances where: (1) only divers can perform the operation (i.e., purely manual means); (2) at least one diver must assist the ROV (i.e., semi-automated means); and (3) divers can be completely replaced by an ROV (i.e., fully automated means). The study concludes that the ROV has usefulness for inspection and navigation purposes, but has significant limitations in the inability to perform any maintenance or repair. One cause has been that prior art ROV design has required adapting third-party attachments (such as manipulators) to the body of the ROV as a means to accomplish any work process, and a lack of modularity (e.g., an ROV is either a swimming vehicle or a tracked vehicle, but can not do both).
One example of such a prior art approach combined a standard tracked ROV with a third-party auger dredge (see, for example, “Robotic Removal of Zebra Mussel Accumulations in a Nuclear Power Plant Screenhouse”, Kotier et al, February 1995). The objective was to search out Zebra Mussel colonies and remove them by auger dredge and pipe the debris to the surface. The apparatus had numerous disadvantages and limitations. It relied upon divers for inspection, having no other means to manually locate and map colonies of Zebra Mussels. The tracked vehicle was restricted to operation on flat and level surfaces. Debris removal was not scalable, being restricted to a single auger head. It lacked other than visual inspection and guidance (via either human or closed circuit camera) and had no means to control turbidity generated by the auger dredge, which resulted in blind operation. An operator, faced with poor visibility, would fail to locate the mussel colonies or even drive the ROV off course and roll it over. The apparatus further lacked automated means to manage the debris hose after it reached the surface so that debris removal and disposal rates could not be continuously coordinated.
A more promising prior art approach was the creation of a special purpose ROV (see, for example, Spurlock, et. al., U.S. Pat. No. 4,763,376) that integrated its work process tools into its frame. The Maintenance, Inspection, Submersible Transport (“MIST” hereinafter) utilized an umbilical to provide electricity from the surface as the means to achieve sufficient power to effectively remove and process debris in large submerged conduits. Electricity was converted to hydraulic fluid pressure to power the hydraulic actuators in various components.
Adjustable legs and arms could address varying diameters of conduit. A drive wheel, mounted on the outboard-end of a pivoting strut, was utilized to provide traction against the surface of the conduit. Cleaning was accomplished via extendable and rotating cleaning struts fitted with four spinning mechanical scrapers. A debris processing unit scooped up loosened debris, pulverized it, and ejected it away from the device.
Although designed for semi-automatic and remote operation, the MIST required a diver to operate it and to perform its intended function. A cage-like frame accommodated a dive chamber for transporting the diver along with the ROV.
Despite its promise over prior art, the MIST (and any similar prior art) still suffered significant limitations and disadvantages: Inspection was limited a operator/diver requirement. Navigation was limited by a fixed, non-articulating frame. Scalability was limited by a fixed and non-expandable configuration. Optimization was limited by conflicting requirements: a diver and deadly high-voltage current in close proximity. Performance was limited by reliance on manual inspection, navigation and optimization, and an inadequate debris recovery system.
Fully automated methods do not require diver involvement but are limited in the types of tasks or environments in which they can perform. For example, the prior art may disclose an apparatus with the ability to perform some level of inspection in an automated fashion, but the same apparatus cannot perform remediation. Similar inflexibility manifests in most of the prior art. This limitation is caused by automated apparatus architecture that is of a monolithic nature and lacking standardized or interchangeable parts. Alternatively, the prior art may disclose an apparatus with the ability to remediate a round, small diameter submerged conduit, but is unable to negotiate obstacles. In all of these cases, divers must be used to compensate for these and numerous other disadvantages and limitations of the prior art apparatus.
The automated ROV (see, for example, Rodocker et. al., U.S. Patent Pub. No. 2007/0276552 A1) incorporates sensors able to perform inspection. The resultant data is compared to pre-determined thresholds and, should a threshold level be exceeded, an appropriate pre-programmed reaction is triggered. Despite various advances applied to inspection and navigation problems, automated ROVs suffer the same limitations and disadvantages of Manually operated ROVs.
Control systems for fully automated apparatus, including various types of autonomous or robotic vehicles, are well known in the prior art, but have seen only limited application to systems for infrastructure remediation. In most cases, they have been applied to apparatus having a fixed mechanical configuration and requiring reengineering whenever that configuration was changed.
U.S. Pat. No. 7,720,570 B2 (Close, et. al.) teaches “Plug-and-Play” attachment of a variety of tool heads and sensors to the frame of a robotic device for subterranean infrastructure rehabilitation. This is accomplished via a “universal interface” (a.k.a. “tool head interface”) for standardized connection of interchangeable tool heads or sensors to the device body, and that is movable with respect to the device body. Tool heads and sensors attached via the universal interface are “self-describing” with respect to functionality. The patent fails to disclose how the mechanical aspect of the interface is accomplished beyond including a “power take-off”, flexibility, and quick connect capability, and does not teach any method for integrating power and communication interconnection into a single bus. Means for accomplishing component self-discovery, self-recognition, and self-configuration upon connection to a network connected to the control system are disclosed, and these determine functional options presented to an operator on a computer display. Means for locating the robot's position (“localization”) are described, including the use of markers detectable by the robot. Movement of a tool head is limited to three degrees of the robot body and three degrees of freedom of the tool head with respect to the robot body. No methods are disclosed for controlled articulation (i.e., movement of multiple parts in different ways at the same time) of a tool head, let alone flexible configuration of a tool head or other attachment to the robot. Although multiple tool heads attached to one robot are disclosed, no means of coordinating the activities of those tool heads is disclosed.
U.S. Pat. No. 6,108,597 (Kirchner et. al.) discloses the use of a planning system for robot navigation, including sensor-based and map-based path planning. An autonomous mobile robot system is provided with a sensor-based and map-based navigation system for navigating a pipe network, taking into account sensor inaccuracy and motion inaccuracy (e.g., due to drift, slip, and overshoot). The system uses position sensing, including recognition of natural landmarks and artificially placed markers, to determine a “plausible position” with respect to a map. A path plan is then developed to reach a goal from the plausible position.
U.S. Pat. No. 7,555,363 B2 (Augenbraun) discloses a multi-function robotic device selectively configurable to perform a desired function in accordance with the capabilities of a selectively removable functional cartridge operably coupled with a robot body. Mechanical characteristics of the functional cartridge are determined automatically. Localization and mapping techniques may employ partial maps associated with portions of an operating environment, data compression, or both. Means to avoid an obstacle are disclosed.
U.S. Pat. No. 6,917,176 B2 (Schempf, et. al.) discloses a gas main inspection system having multiple modules connected in a train, and joint members for interconnecting adjacent modules where the joint members enable articulation of modules in multiple planes and multiple angles with respect to each other.
U.S. Pat. No. 5,548,516 (Gudat, et. al.) discloses a system for positioning and navigating an autonomous land-based vehicle. It teaches means for using a scanning system for obstacle detection, a positioning system to determine vehicle location, and a tracker system to calculate steering and speed corrections.
U.S. Patent Pub. No. 2010/0292835 A1 (Sugiura, et. al.) discloses means for using a planning module, target input interface, a predicting module, and a reactive controller for autonomous robot planning in a dynamic, complex, and unpredictable environments.
U.S. Patent Pub. No. 2009/0234527 A1 (Ichinose, et. al.) discloses an autonomous mobile robot device and teaches means for obstacle detection and path planning for reaching a goal while avoiding the obstacle using various pre-determined avoidance methods.
U.S. Patent Pub. No. 2003/0171846 A1 (Murray, et. al.) discloses methods and apparatus for a hardware abstraction layer for a robot such that the underlying robotic hardware is transparent to perception and control software (i.e., robot control software).
U.S. Patent Pub. No. 2002/0016649 A1 (Jones) discloses a robot obstacle detection system using optical emitters and sensors.
U.S. Patent Pub. No. 2003/0089267 A1 (Ghorbel, et. al.) discloses an autonomous robot crawler for small-diameter enclosed pipes or conduits.
U.S. Patent Pub. No. 2004/0013295 A1 (Sabe, et. al.) discloses an obstacle recognition apparatus and method, including software system for a robot that moves along a floor (planar surface). It is capable of determining the position of the obstacle. U.S. Patent Pub. No. 2009/0292393 (Casey, et. al.) and 2010/0275405 (Morse, et. al.) disclose similar systems for obstacle detection and obstacle avoidance or obstacle following.
U.S. Patent Pub. No. 2005/0145018 A1 (Sabata, et. al.) discloses means to use a wireless sensor network to monitor pipelines.
U.S. Patent Pub. No. 2008/0147691 A1 (Peters) discloses an architecture by which a robot may learn and create new behaviors in a changing environment using sensory input.
U.S. Pat. No. 6,162,171 (Ng, et. al.) discloses a multi-segment autonomous pipe robot frame with articulated joints between the segments.
U.S. Patent Pub. No. 2009/0276094 A1 (DeGuzman, et. al.) discloses an autonomous robot that performs maintenance and repair activities in oil and gas wells, and in pipelines. It uses well and pipeline fluids for locomotion, and sensors, maps, plans, knowledge base, and pattern recognition to plan and achieve goals.
U.S. Patent Pub. No. 2010/0063628 A1 (Landry, et. al.) discloses apparatus and methods for obstacle following (i.e., movement along an obstacle) by a robotic device using a combination of deterministic path determination (i.e., navigation according to a plan) and path by random motion. A sensor system comprising a bump sensor, a debris sensor, and an obstacle following sensor is disclosed.
U.S. Patent Pub. No. 2010/0274430 A1 (Dolgov, et. al.) discloses a method for semiautonomous navigation comprising creating an obstacle free diagram using topological sensor data about a surface.
U.S. Patent Pub. No. 2010/0286827 A1 (Franzius, et. al.) discloses a robot with a method for processing signals from a video or still camera so as to recognize three dimensional shapes and their properties.
While the foregoing prior art discloses various elements used in the present invention, none apply the combination to achieve the synergism, functionality, and benefits of the present invention.
All prior art apparatus and methods for infrastructure remediation, including but not limited to those discussed above, fail to address one or more of the INSOP infrastructure remediation solution requirements, and therefore fail to achieve the advantages and synergy of meeting all of those requirements. Prior art apparatus and methods all have a need for reliance upon manual methods that include divers and surface support crews. These include, but are not limited to, the following, and their numerous combinations, variations, and extensions: divers and their implements; pipeline pigs; specialized apparatus, whether towed, or self-propelled, whether utilizing mechanical means or pressurized water, and whether operating individually or as the central component of a system of supporting facilities; specialized apparatus, whether towed, or self-propelled, whether utilizing mechanical means or pressurized water, and whether operating individually or as the central component of a system of supporting facilities; and, ROV's, whether generalized, special purpose, manual or automated.